The innocent fell prey to his devious scheme. He looked harmless with a below average physique and gait; which in no way hinted at his sinister intent. Sunil Rastogi, 38, father of three daughters was arrested by Delhi police on Sunday. Police was on a lookout for Rastogi in three cases of sexual assault of minor girls that took place in Delhi in last two months.

Rastogi who is a native of Rampur in Uttar Pradesh and had lived in Delhi for 14 years from 1990 to 2004 before shifting to Rudrapur in Uttarakhand was a school dropout and a tailor by profession. His work and life all speaks of a normal life. What shatters this image of normalcy is the crime he committed.

He reportedly abused more than 500 young girls during a period of 12 years.

On 13 December and then on 10 January, Delhi police received three different complaints about sexual assault of three minor girls aged 7 to 10 years. According to the two complainants who filed the complaints on 10 January, a man misled their children aged 10 and 9 years, took them to the staircase of a deserted building and sexually abused them.

What would initially have looked like two different cases of sexual abuse, when investigated by the police, revealed a face that was hidden in the crowd and was extremely ugly.

Here was a man who was on sinister spree. Leaving his home like he is leaving for a regular job, he would end up 'hunting' innocent minor girls.

Representational image. AP

After his arrest Rastogi revealed that he had committed similar offences with young girls in the area of New Ashok Nagar Delhi, Ghaziabad and in Rudrapur, Uttarakhand.

According to Delhi police the accused also disclosed that "Whenever he finds any minor girl going home from school, he used to mislead her on the pretext that her father had sent some clothes and some other articles to give the same to her and take her to an isolated place and raped or tried to rape them".

Dr Manju Mehta, former professor of Clinical Psychology, All India Institute Of Medical Sciences (AIIMS) New Delhi, an expert in psychological disorders in children, adolescents and adults, terms Rastogi's behaviour as "mental illness".

Mehta says, "It is a psychological disorder where these people are attracted towards minors and children only, like it happened in the Nithari case. The accused in that case Surender Koli also use to target young girls and boys and there is a reason behind that. These people are usually very introvert and lack confidence. They feel less threatened by small children so they attack them".

She adds, "These people have immense lack of self worth and self confidence due of which, to satisfy their urge which is usually guided by pervert impulses, they target children."

It is usually found in many cases that the likes of Koli and Rastogi themselves have been victims of sexual abuse in their childhood. But psychologists feel that it is not always the case always. "It is not necessary in all the cases but definitely their fantasies are related to young females", says Dr Mehta

Briefly explaining the profile of paedophiles, National Center for Biotechnology Information which is part of United States National Library of Medicine (NLM) writes, "Pedophiles and child molesters share some characteristics. Most are male, and they can be heterosexual, homosexual, or bisexual. Some prefer adult sex partners but choose children because they are available and vulnerable".

It adds, "The sexual abuse perpetrated may be a one-time incident and may consist only of fondling. Penetration is unlikely with young children. Perpetrators' age ranges from teens to midlife. Most victims are girls, and the perpetrator usually is a relative, friend, or neighbor. The home of the victim is often the setting for the incident. When boys are victims, sexual abuse may take place outside the home, and perpetrators may be strangers. Perpetrators of sexual abuse of children often claim that they themselves were victims of childhood sexual abuse. Psychological profiles are helpful but are compromised partly because many perpetrators are prisoners and control groups are lacking for this research".

Dr Manu Tiwari Psychiatrist at Fortis Escorts Heart Institute & Research Centre, Noida says, "There are three factors behind such sexual deviance. First is personality issues, second is psychiatric illness and third is previous history. Psychiatric illness is most common factor behind such sexual disorder. Paedophile are usually people who are not able to sustain normal adult sexual life so they are attracted to the vulnerable groups.They are also aroused by the alternative ways of sex which is not normal. It is sometimes done under the influence of some substance and sometimes these people have what we call anti-social personality disorder which is not limited to sexual activities".

He adds, "Other factor may be a previous history of sexual abuse. It is found that in many such cases the accused have been victim of the sexual abuse themselves in their childhood".

Further talking about the profile and treatment of such offenders Dr Tiwari adds, "Males are more common offenders and the ratio of male versus female offender is 10:1. Their treatment is very hard as they are non-compliant. The treatment given to them is called cognitive behaviour therapy and meditation which is long term. Their treatment is usually done under court guidance and in custody and there is major chances of relapse as they don't follow up. Usually they are habitual and not opportunistic offenders".